Re: [dpdk-dev] ip_pipeline firewall customization

[Shyam Shrivastav <shrivastav.shyam@gmail.com>]

Hi Cristian

Please see my comments inline (in blue)

>       b) Make required changes in pipeline_firewall_msg_req_add_handler if
> > portid is -1, that is table entry action to be .action =
> > RTE_PIPELINE_ACTION_DROP.
> >
>
> You don't really need to do this for implementing a drop action. You can
> simply create a SINK output port (which basically drops all the packets
> directed to it) and set this as the output port for all rules that drop
> packet.
>
> See ip_pipeline/config/firewall.cfg as example.
>

Yes dropping of packets can be achieved by creating a sink port. However we
need further processing to be done for a packet hitting a pass rule, and
best way for this processing is f_action_hit table handler.  In this
routine we can distinguish between drop/pass actions as
rte_pipeline_table_entry is passed to it, which also contains  portid but
no generic way to  distinguish between normal or sink port.
I think it would be value addition to allow this action in firewall
pipeline, please let me know your thoughts. As for our project looks like
we have to include this.


>
> > 2) I am registering a f_action_hit function for firewall table to perform
> > certain translations if action is pass (RTE_PIPELINE_ACTION_PORT).
>
> What type of actions are you performing? If generic enough, it would be
> interesting to add them to this pipeline, so I encourage you to contribute
> with ideas and code patches.
>
>
Probably it's not generic, involves vlan translation and mac swapping to
inject the "passed" packets back to the router to travel to next hop.
Router injects traffic for filtering to directly connected firewall port
with vlan tag say A , firewall in turn injects pass traffic with different
vlan tag say B back to the router which then does next hop processing.


> >
> > Is this a bug or am I missing something ?
> >
>
> You can make sure no ARP packets are received by the firewall pipeline by
> simply filtering all the ARP packets to a separate RXQ of the NIC port,
> which can be further handled by a separate function.
>
> See ip_pipeline/config/network_layers.cfg as example:
> [LINK0]
> arp_q = 4
>

There are two things here

1) ARP packets should not hit the ipv4 acl which looks like happening, have
not worked on "why part" for now , need to look at the
rte_table_acl_lookup->rte_acl_classify.

2) Yes we can filter ARP packets to a separate queue and to separate lcore
at link level, but need to decide whether its worth it. We are planning to
use ipv4 RSS (with 8 queues, lcores and processors) wherein all arp packets
would get filtered to queue 0 by default and then dropped by ACL.


Thanks and regards
Shyam